Leading the Eagles' assault was Nate Smith, who finished with 26 points to lead all scorers. Twenty-three came in the second half, and 15 were off treys.
"Nate has been struggling a little bit," Zwart said. "But he really stepped it up for us tonight."
Smith also was a menace on defense with five steals.
Devon Hood also had a strong game for Southwest, chipping in 18 points. In the third quarter, Hood came to life, coming away with three steals and pulling down a couple key defensive boards.
"It just got away from us," said Holtville skipper Mike Goodsell. "We're a young team and we just lost our focus."
The host Vikings held their own in the first half, staking an 18-14 lead through the first period and a 32-25 lead at halftime, despite only hitting three shots from the field in the second quarter. Holtville relied on free throws in the second stanza to keep the Eagles at bay.
Holtville went to the line seven times in the second period, as Southwest was whistled for 12 fouls in the first half to the Vikings' five.
In the second half, though, Southwest stopped fouling and the Vikings suddenly went cold from the field.
The Eagles, meanwhile, caught fire. Smith opened the third period by burying a three-pointer and Brian Martinez followed with a move in the lane for a bucket to pull Southwest within two at 32-30.
Holtville managed to keep a slight lead until 3:40 left in the period. Jesse Hoyt hit back-to-back buckets to put the Eagles in the lead for good, 38-37.
Martinez followed with a move along the baseline, Hood hit a pair of free throws, and Smith capped a 11-0 Eagle run with a three-pointer that boosted Southwest's lead to 45-37.
In the closing moments of the period, Smith hit another three and scored on a lay-up, both times taking passes from Martinez and the Eagles enjoyed a 50-41 cushion heading into the fourth quarter.
Southwest used a 12-0 run early in the last period to ice the win. Hood opened the string with a bucket down low, Smith canned a three, Hood hit a basket in the lane, Smith scored in the lane and Brad Goff capped it by burying a trey to lift Southwest into a 62-43 lead.
After that, the Eagles cruised, with Zwart using his bench.
Martinez added 12 points for Southwest, Goff tallied nine and Hoyt contributed four.
Goff also had six assists and four steals.
Jon Singh led Holtville with 16 points, Jacob Freeman sank 13, Eric Cueto had nine, Andres Quesada sank six, Alex Martinez swished five and Isac Mejia added three.
Cueto led the Vikings with 11 rebounds while Quesada had nine and Freeman had eight.
Southwest (12-6 overall, 3-2 Imperial Valley League) is at Central Union High at 7 p.m. Friday while Holtville (8-8 overall, 2-3 Desert League) hosts Calipatria at 7 p.m. Friday.
Brawley 60, Imperial 29
BRAWLEY — Lafayette Lofton scored 18 points Tuesday to lead Brawley Union High's boys basketball team to a 60-29 win over Imperial.
Mark Rivera added 13 points for Brawley and Miguel Melendez chipped in 12.
Marwan Ratliff led Imperial with 12.
Brawley (13-5 overall, 5-0 Imperial Valley League) hosts Calexico at 7 p.m. Friday. Imperial (2-3 Desert League) is at Palo Verde at 7 p.m. Friday.
Calipatria 72, Vincent 62
CALIPATRIA — Vontray Taylor scored 21 points as Calipatria High's boys basketball team outran Vincent Memorial on Tuesday 72-62.
Ezequiel Navarro hit 16 points for Calipatria and Daniel Thomas added 14.
Dominic Jacobelli led Vincent with 33 points.
Calipatria (11-10 overall, 2-1 Desert League) is at Holtville at 7 p.m. Friday.
Palo Verde 66, Calexico 51
BLYTHE — The Calexico High boys basketball team fell to 3-2 in the Imperial Valley League with a 66-51 loss to Palo Verde here Tuesday.
Leading Calexico were Alex Marin with 17 points and Chris Ramsey with 13.
La Quinta 89, Central 52
LA QUINTA — Luis Robles scored 15 points and Randy Andrews added 13 as Central Union High's boys basketball team remained winless on the season with an 89-52 loss to La Quinta on Tuesday.
Robles also had three rebounds, three assists and one steal. Vincent McSee added nine points and five boards.
Central (0-21 overall, 0-7 Imperial Valley League) hosts cross-town El Centro rival Southwest High at 7 p.m. Friday.